Rifle Scopes Benefits of a 34mm tube over a 30mm tube?

[earthquake]

Barring the fact that I'm interested in more magnification and I want a different reticle in my scope, I'm thinking of upgrading from my current 20x scope with 30mm tube, to a Bushnell XRS. I really like the G2 reticle over my current mil-dot, and when I got my hands on one of these scopes over at Mile High the other day, I was blown away by how clear the image AND reticle were at max power! But, it's a 34mm tube and I'm not sure I need that.

I think I understand that a fatter tube gives you more travel in elevation and windage, but since I'm shooting a 6.5 Creedmoor only out to about 1,000 yards, I've found I only need ~7.6 mils or so...less than one full rotation of my elevation knob. Therefore, what would I need a 34mm tube for? I'd also have to trade or sell my Spuhr mount as well for a 34mm version. Should I stick with the 30mm line of optics, or is there an advantage I'm not thinking of for making the switch to the 34mm Bushnell?

 

[Captain Kirk]

Just additional room inside the scope for the erector which means more lelevation and windage. It was believed the tube diameter aided in light transmition, which we now know to be faulse. The 34mm tube is more robust, and if the optic you want to purchase has a 34mm tube as does the Bushnell, it makes sense to switch.

Kirk R

 

[Goin'Hot]

If you like that scope then you'll have to make the jump up to 34mm. March and SWFA both make 30mm scopes with a bunch of elevation in them.

The benefit of a 30mm tube is that you can use Burris signature rings with the plastic inserts to gain you additional elevation in your mount. I put a March on my 22 trainer with a 20 moa base and 10 moa in the rings and I have 18.3 mils of up travel in the scope. The only way I could have done that (with reasonable CL height) with a 34 mm tube would have been a custom base.

 

[holdoff]

When I have compared larger diameter tubes vs 30mm, they seem to offer a slightly larger FOV for a given power. This may not hold up 100% of the time, and I am sure that you could find brand x 30mm scope beat a brand y 34-35mm tube, but looking through a SWFA 5-20 vs a Vortex Razor 5-20 and a Bushnell 3.5-21 seemed to bear this out on target.